Baby is now pretty well built portion wise even though it still has little body fat and its skin is thin. The structures of the spine begin to form -- All 33 rings, 150 joints and 1000 ligaments. The tiny brain is growing rapidly, and the baby is starting to fill the space in your uterus. The uterus is now about the size of a soccer ball and mom looks pregnant.

Your baby's hands are now fully developed, although some of the nerve connections to the hands have a long way to go. Dexterity is improving. Your baby can make a fist and clasp objects placed in palm. Exploring the structures inside your uterus may have become baby's prime entertainment. Fascinated by the amount of tactile stimulation a fetus gives itself; it touches a hand to the face, one hand to the other hand, clasps its feet, touches its foot to its leg, its hand to its umbilical cord. Twins will explore each other and begin their bonding. See: Twins 3D sonagram movie.

Blood vessels of the lungs develop. Your baby's nostrils begin to open. The nerves around the mouth and lip area are showing more sensitivity now. Their swallowing reflexes are developing. Baby can hear sounds outside the womb and the brain cells are starting to mature also. Already it can learn and remember and can recognise its mother and fathers voice. The inner ear bones have hardened so hearing is more acute. Baby may hear your partner's voice more easily than yours, as baby is sensitive to a deeper pitch.

Babies born at 25 weeks of pregnancy have about a 50% chance of survival.

Rumaisa and her non-identical twin, Hiba were born in Sept. 2004 14 weeks premature by c-section. At birth, Hiba weighed 1 pound and 4 ounces (567g) while Rumasia weighed just 8.5oz (244g) and was just 10 inches (25.5cm) long.